body{
    background:url(https://bkimg.cdn.bcebos.com/pic/c75c10385343fbf2b211d073b737dd8065380cd72100?x-bce-process=image/watermark,image_d2F0ZXIvYmFpa2UxODA=,g_7,xp_5,yp_5/format,f_auto) ;
    background-size: cover;
}